Johannesburg: Lasith Malinga's five-wicket haul and Dinesh Karthik's whirlwind 74 went in vain as Chennai Super Kings eked out a narrow six-run win over Mumbai Indians in an inconsequential Group B match of the Champions League Twenty20 here on Saturday.

Even before the first ball was bowled, the match was rendered a dead-rubber after Lions notched up a five-wicket victory over Yorkshire earlier today to become the second team from Group B to reach the semifinals, thus knocking out both Chennai and Mumbai Indians.

However, both the IPL teams ensured that the spectators at the New Wanderers stadium don't go back disappointed as they enthralled them with an edge-of-the-seat thriller which went down to the wires.

Sent into bat, CSK openers du Plessis (52) and Murali Vijay (39) initially lifted the spirit of the spectators with an entertaining 86-run stand in just 49 balls, studded with 10 fours and three sixes.

However, Malinga spoilt their party as he notched up a five-wicket haul in his four overs. The Sri Lankan pacer dismissed du Plessis, Suresh Raina (8), Mahendra Singh Dhoni (35), Albie Morkel (0) and Wriddiman Saha (5) to help Mumbai restrict Chennai to 173-8.

Karthik then led the Mumbai runchase with a scintillating 45-ball 74, which was studded with four fours and six sixes, and almost took them to the brink of victory. Pollard also blasted a 17-ball 31 with the help of one four and three sixes but MI still fell short by six runs in the end.

The credit goes to Man of the match, Ben Hilfenhaus (2/14) who led the bowling attack brilliantly. He was supported well by Albie Morkel (2/28) and Ravindra Jadeja (2/47) and part-timer Faf du Plessis (1/3).

Chasing 173, Mumbai Indians failed to get a good start and were reduced to 21-2 in 4.4 overs.

Opener Sachin Tendulkar's poor run continued and he was the first to be dismissed by Ben Hilfenhaus in the fourth over. In the next over, Morkel dismissed the other opener Smith (13) as MI slumped to 21-2.

Rohit Sharma (32) and Karthik then tried to resurrect the innings with the former picking up three sixes but with the Chennai bowlers bowling in tendem, the runrate kept creeping up all the time.

Karthik too then got into the act, hitting Jadeja for a six over midwicket and successive fours at the same area to notch up 19 runs off the over. MI were 77-2 in 11 overs at that stage.

Morkel was brought back into the attack and the South African picked up Rohit in his first delivery to reduce MI to 85-3 in 12.1 overs.

Ambati Rayudu then handed over his wicket to du Plessis. Keiron Pollard and Karthik then brought up the 100 in 15 overs, still needing 74 runs from 30 balls.

Karthik picked up a four and a six off Ashwin to reach his fifty and then plundered a boundary off Doug Bollinger to keep CSK in the hunt.

Needing 51 off 3 overs, Mumbai raised 24 runs in the 18th over, courtesy a six by Karthik and a couple of sixes and a four by Pollard.

Hilfenhaus was brought in to bowl the 19th over and the Australian, although conceded a six, got rid of Karthik off a slower delivery.

Needing 19 runs off six balls, Pollard blasted Jadeja's first ball over the long-off but a stunning catch by Raina in the next ball put brakes to Mumbai's chase.

Earlier, Chennai went on to a brilliant start but Pragyan Ojha brought the first break through, cleaning up Vijay after the Tamil Nadu batsman danced down the pitch in pursuit of another big hit. Malinga then struck twice in two balls to reduce them to 101 for three in 10.5 overs.

Dhoni (35), who survived a run-out chance early in his innings, provided a much-needed spark with an entertaining 19-ball 35, laced with three fours and two sixes, before becoming a victim of Malinga.

Once the captain was back in the pavillion, rest of the batsmen tried to accelarate and even though they perished in regular intervals, they did enough to help Chennai put up a challenging score on board.

Earlier, opening the innings, Vijay blasted Ojha for an inside out shot over cover for the first six of the innings in the fifth ball. du Plessis then went berserk against Mitchell Johnson, picking up two fours and a six in the last three balls of the third over.

Vijay too continued his rampage, blasting Dhawal Kulkarni for a six over midwicket and consecutive fours at the covers and point area in the next over as CSK raised 15 runs.

Malinga was then introduced into the attack but du Plessis didn't pay any respect to the bowler and clobbered him for three overs to take Chennai to 62 for no loss in 5 overs.

Johnson gave away four runs in the next over, while Ojha conceded nine runs, which included a four by Vijay.

MI skipper Harbhajan Singh then brought himself into the attack but Vijay picked up two fours in the fourth and fifth ball to take his team to 86-0.

Mumbai clawed back after that with the help of Malinga as runs dried out and wickets started to tumble.

However, Dhoni kept the scoreboard ticking and picked up a four and six at the deep backward point to help Chennai accumulate 13 runs of the 14th over.

In the 17th over, Dhoni picked up a six and a four in the first two ball but Malinga cut his innings short when he had him caught at backward point by Smith.

In the final over, R Ashwin blasted a four and six over over third man off the last ball to swell Chennai's total to 173-8.